days = {"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"}
print(days[4])
a = {x = 10,y = 20}
print(a.x)
x = {math.sin(0),math.sin(1),math.sin(2)}
print(x[2])
print(arg[2])
-- 记录式
polyline = {
    color = 'blue',
    tickniess = 2,
    npoints = 4,
    {x = 0, y = 0},
    {x = -10, y = 0}
}
print(polyline[1].x)
-- 特殊符号用[] 包裹
opnames = {
    ["+"] = "add", ["-"] = "sub",
    ["*"]= "mul", ["/"] = "div"
}
i = 20; s = "-"
a = {[i+0] = s,[i+1] = s..s,[i+2] = s..s..s}
print(opnames[s])
print(a[22])
for _,value in pairs(opnames) do
    print(value,opnames[_])
end
-- {"r","g","b"} = {[1]="r",[2]="g",[3]="b"}
-- {x = 0, y = 0} = {["x"] = 0,["y"] = 0}